Automatic electrical levelling switch for silo unloaders



AUTOMATIC ELECTRICAL LEVELLING SWITCH FOR SILO UNLOADERS Filed March 19, 1965 INVENTOR. D. fiifz man W Z Y W V 3 av aw W A W m w C l. 0 W

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pfTR/VEY Unite States Patent 3,398,973 AUTOMATIC ELECTRICAL LEVELLING SWITCH FOR SILO UNLOADERS Calvin D. Heitzman, Spencer, S. Dair. 57374 Filed Mar. 19, 1965, Ser. No. 441,165 1 Claim. (Cl. 214-17) My invention relates to a switch for silo unloaders.

An object of my invention is to provide a mercury switch arrangement which is attached to a standard silo unloader, and whereby the switch will operate an electric circuit to lower the silo unloader automatically when necessary so as to continue the unloading action.

A further object of my invention is to provide means for adjustably positioning the switch.

A further object of my invention is to provide a warning light arrangement for indicating to the operator when the unloader should be lowered at the necessary intervals.

A further object of my invention is to provide an arrangement which can be readily attached to a silo and the unloader.

With these and other objects in view, my invention consists in the construction, arrangement, and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

FIGURE 1 is a sectional view taken through a silo showing my device as attached to a silo unloader,

FIGURE 2 is an enlarged detail of the adjustable switch,

FIGURE 3 is a modification,

FIGURE 4 is a wiring diagram, and

FIGURE 5 is a further wiring diagram.

In describing my invention I have used dotted lines to illustrate for clarity the principal portions of the silo unloader, and the character indicates a motor which drives a shaft 11 which in turn through the belt 12 will drive a suitable gear arrangement to drive a pair of augers 13, these augers having suitable small blades attached thereto for conditioning, and for conveying the silage toward the blower housing 14 in which is a suitable fan which blows the silage through the discharge spout 15, which is adapted to blow the silage within the vertically positioned housing 16, through the bottom 17 of which the silage will be discharged for feeding the animals, etc.

The character 18 indicates a cylinder having the spokes 19 attached thereto, which cylinder is rotated by the shaft 20 suitably driven by the motor 19, and which rotates the silage unloader arrangement which also includes the end wheels 21 which travel along the outer periphery of the silage 22. The character 23 indicates horizontally positioned wheels which bear against the inside wall 24 of the silo to maintain accurate positioning, and the character 25 indicates a yoke attached at 26 to a cable 27 which passes over the upper pulley 28 supported at 29 from the roof portion 34 of the silo. The character 31 indicates silo unloader framework portions.

When operating the standard silo unloader, it is necessary in the devices heretofore used to manually lower the cable 27 by means of a winch when the discharge through the opening 17 begins to diminish, thereby providing a rather cumbersome method for lowering the silo unloader when necessary. The auger 13 is adapted to convey the material inwardly, and when the silage becomes partly frozen or frozen at the lower positions shown in FIGURE 1, the lowering action by the operator is rendered more uncertain, and it is the object of my invention to provide an automatic arrangement which will lower the unloader automatically without the attention of the operator.

To provide this result I pass the cable 27 through an "ice opening 32 provided in the roof 30 which cable passes over a further pulley 33 attached to the bracket 34, the cable 27 thence passing about a reel 35 which is driven by means of a shaft 36 which is driven by a suitable chain of gears by an electric motor 37, said gears being mounted within the gear casing 38, the shaft 36, however, rotating in such a direction that when the contact is established as to unreel the reel and to thereby allow the cable 27 to drop in the direction of the arrow 39' to allow the silo unloader to drop by gravity. The casing 38 is attached to the wall 40* of the silo as at 41.

The character 42 indicates a plate having the extending portions 43 which are clamped by means of the clamps 44 to the framework portion 31, and pivoted at 45 to the plate 42 is an adjustable member 46 which can be adjustably secured by means of the wing nut 47 which is attached to the plate 42. The character 48 indicates a glass bulb having a mercury contact 49 therein adapted to cover the contact members 50 when in the position shown.

The device operates in the following manner. As shown in FIGURE 2 the device is operating, or in other words, the contact is established which will actuate the motor 37 which will cause the reel 35 to unreel, which will thereby allow the silo unloader to drop until the outer wheels 21 will be forced upwardly by the outer annular portions of the silage 22 whereby the inner end of the bulb 48. will drop in the direction of the arrow 51 (see FIG- URE 2) and the mercury will then fall away from the contacts Stl thereby breaking the circuit and the silage unloader will continue to operate in this particular plane or elevation until the wheels 21 will again fall below the Operating level to again close the contacts, this operation being constantly repeated until the silo is completely unloaded, and without any attention by the operator.

The adjusting device 46 is important in that the bulb 49 can be set in any predetermined level desired by means of the wing nut 47 consistent with the quality of the silage, and especially when the silage is in a frozen or similar condition, this adjustment providing means whereby the range between the contact and the broken contact is either made larger or smaller depending on the material as stated. The silage is generally cut away along a substantially conical surface 52, and it will be noted from the foregoing description that the automatic switch arrangement will provide the functions and advantages above stated.

FIGURE 3 illustrates a modified arrangement wherein the switch and practically all the other parts are identical, however in this modification the character 53 indicates a bracket attached to the wall 46 which bracket supports a reel 54 operated manually by the handle 55, the character as indicating an electric light bulb attached to the socket 57 which is attached to the wall 49, the circuit of this form being shown in FIGURE 5, and in thisarrangement, when the light 56 is actuated by means of the mercury contact it will indicate to the opera-tor that the reel 54 should be slightly unreeled to allow the silo unloader to drop.

It will now be noted that I have provided the advantages mentioned in the objects of my invention with further advantages being apparent.

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claim any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

In combination with a silo unloader and a silo in which said silo unloader operates, a gravity operated switch attached to said silo unloader, a circuit connected to said switch, an electric motor operated by said switch and attached to said silo, a reel operated by said motor, a cable attached to said silo unloader and to said reel, pulleys attached to said silo over Which said cable passes, said switch being actuated when portions of said silo unloader drop-be1ow a predetermined level to thereby operate said reel to cause said silo unloader to drop, said switch including a mercury contact member, said mercury contact member being positioned so as to make and break contact incidental upon positioning of said silo un loader portions on silage, means for adjustably positioning said mercurycontact member-to different angular positions including an arm to which said mercury contact member is attached, a bracket attached to said silo unloader to which said arm is attached, means for adjustably positioning said arm.

References Cited by the Examiner UNETED STATES PATENTS 2,663,594 12/1953 Dennick 2l4--l7 X 2.995,260 8/1961 McCann et al. 2l4-17 3,058,102 10/1962 Burrows et a1. l98-40 X GERALD M. FORLENZA, Plimary'Examine r.

ROBERT G. SHERIDAN, Examiner. 

